Grinding apparatus



Jan. 6, 1959 susuMu KAKlUcHl GRINDING APPARATUS Filed Feb. 21, 1957 "lll/lll.

IZ, l will Susu/wu .KAM/35W" ATTORNEYS Jan. 6, 1959 sUsUMU KAKlucl-'u 2,867,057

GRINDING 'APPARATUS Filed Feb. 21, 1957 2 SlleetS-Sh'le'el' 2 INVENTOR. .Sigi/MU HAK/UCH/ i'-f ATTORNEYS .United States Pattt GRINDING APPARATUS Susumu Kakiuchi, Tokyo, Japan Application February 21, 1957, Serial No. 641,692 l 3 Claims. (Cl. 51-51) The present invention relates to a grinding apparatus and is more particularly concerned with a plane grinder characterized in that the reciprocating velocity of the whetstone and the revolving velocity of the material to be ground are controlled relative to one another so as to grind all parts of different revolving radii of said material at the same relative velocity.

Referring now more particularly to the accompanying drawings:

Fig. l is a diagrammatic sketch of the present grinder and its control system.

Fig. 2 is an enlarged detailed sectional view of an oil controlling valve forming part of the present invention.

Fig. 3 is an enlarged sectional view of a portion of said oil controlling valve taken at right angles to Fig. 2.

Figs. 4A and B are views taken respectively on lines A-A and B--B of Fig. 3.

Fig. 5 lis a top view partly in section of the electromagnetic chuck andthe raising and lowering means therefor; and

Fig. 6 is a side elevation of the electromagnetic chuck and supporting frame with the raising and lowering means therefor being shown in cross section.

In the accompanying drawings, wherein like and corresponding parts are designated by similar reference characters, numeral 1 refers to a grinder slidably mounted on a suitable machinery frame (not shown). A whetstone 2 is rotatably carried at the front end of the grinder and is driven by a motor 3.l There is also provided a material holder 4 which is supported by a frame 5 for revolving and moving up and down under the whetstone 2 as will be explained more fully hereinafter. On the plane surface of the holder 4, an electro-magnetic chuck 5 or like means for retaining the material to be ground is arranged, so as to enable the revolving whetstone 2 to grind the upper plane surface of the revolving material held on the electro-magnetic chuck 5. Grinder 1 has on'its lower surface a suitably tapered plate cam 6 which is :in contact with a vertically movable rod 8 supported elastically by spring 9 on the bottom of supporting chamber 7. Both sides of said rod 8 has racks in engagement with gear wheels 12 and 13 which respectively operate the oil controlling Valves 10 and 11. Y

From the rear end of grinder 1 there extends a `sup- -porting rod 14 with which a piston rod 17 of piston 16 is.connected. The inner circumference of said holder 4 has teeth 4 therearound to be engagedv by a driving wheel or pinion 1S driven by an oil pressure motor 19'. The driving wheel 18 may be a gear wheel or friction wheel, but when the wheel 18 is a friction wheel, the inner or outer circumference of holder 4 to be contacted thereby istoothless. l

The vertical motion of the material holder 4 isv controlled by means of a ratchet 20 connected to a shaft 20 which is driven and rotated by a pawl 23 moving with the piston rod 22 of a cylinder 21. Tov said cylinders 15 and 21, oil controlling valves and 11 and oil presc CC j of the piston 16 of cylinder 15. At the same time, the

oil existing in the left side of the piston 16 is returned to the oil tank 24 through the pipe 30, switch valve 28 and oil return pipe 31. Pipes 29 and 30 have respectively a branch pipe 32 connected with cylinder 21 for sending the oil to the cylinder and a branch pipe 33 connected with cylinder 21 for returning the oil in cylinder tothe oil tank 24. In the meantime, the oil running in the pipes 32 and 33 acts on the piston rod 22 in cylinder 21 anderevolves the ratchet 20 by pawl 23 to effect an `automatic upward motion of material holder 4.

VNext, the switch valve 28 is switched over. Then, the oiladvances from pipe 30 to the left side of cylinder 15, and in consequence the piston 16 is moved in the opposite direction by which the grinder 1 moves from holder 4. The oil returns from cylinder 15 to oil tank 24 through pipe 29, switch valve 28 and oil return pipe 31.

` In`the system operating oil pressure motor 19, the oil is supplied to oil controlling valve 11 through an oil pipe 34 by means of pump 35 from tank 24, and consecutively to the oil pressure motor 19 through the pipe 37,'rf`1turning to oil tank 24 through the pipe 38. Pipe 34 has a pressure controlling valve 39 interconnected therein and pipe 25 also has a pressure controlling valve 40 included therein.

Under such an arrangement of oil pipes; the reciprocationof grinder 1 moves the rod 8 vertically by means of the V-cam 6, and the rod 8rotates the gear 12 which controls valve 10 and adjusts the quantity of oil flowing to valve'28. The adjusted flow of oil moves to cylinder 15 'andcontrols the movement of piston 16 and grinder 1, soV that the speed of longitudinal movement of grinder 1 is` gradually increased when it is advanced towards holder 4 but is gradually reduced during its movement therefrom. At the same time, the gear 13 is rotated by said rod 8, and by valve 11 adjusts the supply of oil to oil pressure motor 19 so that the speed of rotation of material holder 4 is gradually increased when grinder 1 advances .thereto and is gradually retarded when the grinder 1 moves therefrom, thereby bringing the whetstone 2 rotating at a definite speed and all portions of the rotating materialen the material holder 4 to the same relative speed.

The construction of oil controlling valves 10 and 11 is as follows: A control cylinder 42 is slidably mounted in the bore of a supporting cylinder 41 and a rotatory cylvirider 43 is rotatably mounted in the bore of said control cylinder. One end of the control cylinder 42 has a threaded recess with a screw rod 44 in threaded engagement therewith and bearing against spring 45 in said recess'to allow the rod 44 to rotate and move cylinder 42 longitudinally al limited distance. The outer end of the screw rod 44 has a hand wheel ,46 xedly connected thereto, and the controlfcylinder 42 goes in or out of Acylinder 41 according to the direction the hand wheel 46 is revolved. Also, the outer end of the cylinder 43 has either gear 12 or 13 xedly connected thereto which iszin` meshedengagement with one of the racks provided on each side of the verticallly movable. rod 8 and which is thus rotated by the vertical motion of the rod 8. The turning of gear 12 or 13 revolves the rotatory cylinder 43 in the control cylinder 42. IThe bore of support cylinder 41 isV provided with circular grooves 47 and 48 at proper intervals therealong. The groove 47 is connected with either oil pipe 25 or 34, and groove 48 is connected with either oil pipe 25 or 37. In the control cylinder 42 and rotatory cylinder 43 there are provided passages 49A and 50, respectively, opening into groove 47, while in the control cylinder 42 and rotatory cylinder 43 there are provided passages 51 and 52 respectively, inthe shape and position shown in Figs. 3 and 4 and opening into groove 48. Therefore, according to the extent of the longitudinal movement of control cylinder 42 and rotation of rotatory cylinder 43, the open area of each of said passages and the volume of oil passing therethrough is completely regulated. Thus, when the grinder 1 is advanced due to the adjustment of control cylinder 42, the vertically movable rod 8y goes up, and

- the gear 12 is rotated by the rack on the one side of the rod` S. The rotation of gear 112 causes the rotatory cylinder 43 in valve 10 to rotate, resulting in that the open area of said passages gradually becomes narrow and accordingly the ilow of the oil supply to cylinder and speed of longitudinalV movement of grinder 1 are gradually reduced. At the same time, the gear 13 is acted on by the rack on the other side of the rod 8, and the rotatory cylinder 43 in valve 11 is rotated in the opposite direction to cylinder 43 of valve 12. Then, the passages 50 and 51 are fully opened in valve 11 and the supply of oil to pipe 37 is gradually increased, and on that account the rotating velocity of oil pressure motor 19 and that of material holder 4 are gradually increased.

Also, when the grinder l is withdrawn from holder 4, the vertically movable rod 8 is pressed down by the cam 6, and gears 12 and 13 and rotatory cylinders 43 of each valve 10 and 11 are rotated in the direction opposite t0 the above. Thereby the volume of oil and longitudinal movement of grinder 1 are gradually increased and the rotation of material holder 4 increases its speed.

The rotating velocity of material holder 4 is changed in this way in relation to the change in velocity of the longitudinal movement of grinder 1, and the relative rotating velocity or the whetstone 2 and the material to be ground becomes equal in all portions of the material. The longitudinal movement of grinder 1 can be changed by switching over the valve 28 by hand, or the reciprocating motion of grinder 1 can be changed automatically by switching over the valve 28 by means of an element to be contacted by the grinder 1 at the end of each stroke of movement of the said grinder.

With reference to Figs. 5 and 6 the electromagnetic chuck 5 and its `holder 4 is rotatably supported on said supporting carriage 5 slidably positioned on a further fixed supporting frame 57. Shaft of ratchet 20 has a gear 53 tixedly mounted thereon with'the end of said shaft being rotatably supported within gear box 56. A further gear 54 in meshing engagement` with gear 53 but at rightangles thereto is tixedly mounted upon a shaft 5S likewise rotatably supported by said gear box and having a threaded end portion 55 in threaded engagement with the threaded bushing 58 carried by said supporting frame 5.

Upon the rotation of ratchet 20 shaft 20' through gears 53 and 54 rotate shaft 55 causing bushing 58 to be raised or lowered by its engagement with threads 55'. Thus supporting frame 5,'material holder 4 and chuck 5 are raised and lowered relative to the wheel 2.

In the plane grinder thus constructed, when a finishing grind of level-rotating material is acted on by the whetstone 2 which is regularly rotating, the rotating velocity of the material is changed in accordance with the levelmoving velocity of the whetstone 2 to utilize such relative velocity equally on every portion of said material, so as 4. to make the face on any part of the material definite and also to equalize all lapped parts, resulting in that a linlshing grind of high precision can be obtained with the least consumption of whetstone.

The apparatus of the present invention is not only applicable to the plane grinder but also to all other machine tools which are operated by oil or other liquid pressure.

What I claim is:

l. A grinding apparatus comprising a grinder slidably mounted for longitudinal reciprocation and including a rotatably driven whetstone positioned laterally of the direction ot longitudinal reciprocation of said grinder, a rotatably mounted and vertically movable material holder,

a hydraulic motor connected to said holder for rotating ,p

the same, hydraulically operated means for raising and lowering said holder, a cylinder, a piston slidably mounted inl said cylinder and connected to said grinder for reciprocating the same, a source of fluid under pressure, a system of passageways connecting said lluid source to said motor, said hydraulically operated means and said cylinder, a cam' carried by said grinder, a rod in contact with said cam for being reciprocated thereby, a plurality of valves in said system capable of varying the relative ow of uid to said motor and said cylinder and connected to said rod for being operated thereby and a control valve in said system for changing the flow of iluid to' said cylinder to change the direction of movement of said grinder. I

2'. A grinding apparatus as claimed in claim l wherein said rod' has racks provided o-n opposing sides thereof, a plurality of pinions are each in meshed engagement with one of said racks and connected to one of said plurality of valves for operating the same upon reciprocation of said rod.

3. A grinding apparatus as claimed in claim l wherein each of said plurality of Valves comprises a cylindrical supporting cylinder, having a plurality of grooves provided inY the bore thereof, a control cylinder slidably mounted in the bore of said supporting cylinder and having passageways therethrough each communicating with onel of said grooves, means for adjusting the relative position' of saidhcylinders longitudinally of one another, a rotary cylinder rotatably positioned in the bore of said control cylinder and having a plurality of passageways therethrough each opening into one of said control cylinder passageways, means connecting said rotating cyl inde'r to said r'od for being rotated thereby, the support cylinder of one of Said plurality of valves having one groove connected to said source of fluid and another groove connected to said valve, the support cylinder of a secondy of said plurality of valves having one of its grooves connected to said source of fluid and another of its grooves connected to said motor, and a plurality of pinions each xedly connected to the rotary cylinder of one of said plurality of valves, said rod having racks carried o'n opposing sides thereof each in meshed engagement with one of said pinions for rotating said rotary cylinder varying the amount of tluid owing through said rotary cylinder bore and passageways whereby the rotary speed of said holder will be in relation to the speed of longitudinal movement of said grinder for obtaining an equal grinding of all portions of said material.

References Cited in the tile of this patent UNITED STATES PATENTS 1,909,155 Webster May 16, 1933 1,938,439 Remington Dec. 5, 19.33 2,018,847 Fraser Oct. 29 1935 2,402,305 Sutton Juno 18, 1946 

